3052: clean exit

[KevinGimbel]

A wrong TERM value can cause k9s to crash, instead of crashing we can log a warning and silently set the variable for the duration of k9s' execution with os.Setenv. We recommend setting this variable in the README.md anyway (during the Preflight checks)

I've tested it with MacOS and would like to test on Linux as well.

How to test

Set TERM to xterm-ghostty

export TERM=xterm-ghostty

Run k9s, it panics:

k9s
panic: exit status 1

goroutine 1 [running]:
github.com/derailed/k9s/cmd.Execute()
        github.com/derailed/k9s/cmd/root.go:72 +0x80
main.main()

Run this branch, it works:

go run main.go
WARN: $TERM must be set to 'xterm-256color', got 'xterm-ghostty'
<k9s starts normally>

[KevinGimbel]

I accidentally added a WIP from another local branch to this PR, which I reverted again. I can also scrap and re-create the entire PR / branch if needed. :)

[KevinGimbel]

@derailed anything else I can do so we can merge this MR? Seems to be low hanging fruits IMHO :)

[derailed]

@KevinGimbel Thanks Kevin! No sure we want to automatically set this. I think it make sense for nix platforms but not sure how it should work on other. Also this is documented and you should only have to do this once if misconfigured??

[KevinGimbel]

@derailed I agree about the documentation, but it feel like it came up more often over the past weeks although I now only find (#3052) with a clear reference.

Maybe an exit and link to the documentation would work? I feel as it is people may be discouraged from using k9s if it fails silently.

[derailed]

@KevinGimbel Tx Kevin! I think that's a great idea.

[KevinGimbel]

@derailed I completely forgot about this PR 🙈 - I replaced the code so that the variable is not set automatically. Instead a Link to the documentation is printed and k9s exits with status code 1.

[github-actions]

This PR is stale because it has been open for 30 days with no activity.